Variable vane ring



May 9, 1967 K. o. JoHNsoN VARIABLE VANE RING Filed March 5, 1965 3 Sheets-Sheet 1 INVENTOR. /fezzzze/z Q Jazzsozz A 7 TOP/V57 May 9, 1967 K. o. JOHNSON 3,318,513

VARIABLE VANE RING Filed March 3, 1965 3 Sheets-Sheet 2 I N VEN TOR.

5 Sheets-Sheet 5 May 9, 1967 K. o. JoHNsoN VARIABLE VANE RING Filed March 3, 1965 United States Patent ce 3,318,513 Patented May 9, 1967 3,318,513 VARIABLE VANE RING Kenneth 0. Johnson, Camby, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Mar. 3, 1965, Ser. No. 436,732 8 Claims. (Cl. 23o-114) This invention relates generally to inlet guide vanes for a compressor and more particularly to an inlet guide vane arrangement for a compressor having variable pitch vanes.

It is well-known in the :art to provide variable pitch inlet guide vanes for a gas turbine compressor in order to improve the operation and performance thereof under off-design operating conditions. Among the problems associated with the utilization of variable pitch vanes in a compressor inlet is their incorporation together with control means into an existing compressor design without radical alteration thereto.

It is therefore -an object of the present invention to provide an improved variable pitch inlet guide arrangement.

Another object is to provide an improved variable pitch inlet guide arrangement which can be incorporated into an existing compressor design with ease and without radical alteration to the existing compressor design.

Another object is to provide an improved variable pitch inlet guide arrangement which is compact, rugged, light in weight and easily assembled.

Another object is to provide an improved variable pitch inlet guide arrangement wherein the vanes may be adjusted easily and without binding.

The exact nature of this invention as Well as other objects and advantages thereof will be readily apparent Ifrom consideration of the following specification relating to the annexed drawings in which:

FIGURE l1 is an elevational view partially in cross section of a portion of a compressor in which is incorporated a preferred embodiment of the invention.

FIGURE 2 is an enlarged elevational view of a portion of FIGURE 1.

FIGURE -3 is a section of the apparatus taken substantially along the line 3 3 of FIGURE 1 and looking in the direction of the arrows.

FIGURE 4 is a plan view partially in cross section with some of the parts broken away and taken substantially along the line 4 4 of FIGURE 3 looking in the direction of the arrows.

FIGURE 5 is a section taken substantially along the line 5 5 in FIGURE `3 and looking in the direction of the arrows.

FIGURE 6 is an enlarged view of a portion of FIGURE 3 showing the actuating means for the variable pitch vanes.

FIGURE 7 is a section taken substantially along the line 7 7 of FIGURE 6 and looking in the direction of the arrows.

FIGURE 8 is a section taken substantially along the line 8 8 of FIGURE 6 and looking in the direction of the arrows.

FIGURE 9 is the section shown in FIGURE 7 with some of the parts in a different position.

Referring now more particularly to FIGURE 1, there is shown an annular inlet 12 in axial alignment with an axial liow multistage compressor indicated generally at 14. The inlet guide has a cylindrical housing 16 witha hub 18 held concentrically therein by a plurality of struts 20. An annular inlet passage 22 bounded by hub 18 and the housing 16 has a plurality of guide varies 24 adjustably mounted therein. The compressor 14 comprises a casing 26 having a shaft 27 extending through it and journaled in the hub 1'8. A plurality of discs 28 `are splined to the shaft 27 for rotation therewith. The discs 28 have rotor blades 29 attached to the peripheries thereof. Alternated with the rotor discs 28 are stator vane rings 30 which carry blades 32 and which may be attached to thecompressor casing 26.

In FIGURE 2, a single `guide vane 24 is shown in greater detail. The guide vane 24 has a stub shaft 31 on its inner end which is journaled in an inner shroud ring 33. The inner shroud ring 33 comprises a pair of rings 34 and 35 which mate to form a plurality of apertures 36 as can more easily be seen in FIGURE 4. A Tellon ring or bushing 38 disposed between the aperture 36 and the stub shaft 31 has a -anged portion which acts as a thrust bearing surface. Referring to FIGURE 5, doWelS 37 locate the inner shroud ring halves 34 and 35 with respect to each other while bolts 39 attach the rings to the hub 18. An O-ring seal 41 is provided between shroud ring 34 and hub 18. Referring back to FIGURES 2 and 3, a hook 40 depends from the inner end of the guide vane and extends into an annular cavity 42 between the inner shroud rings 34 and 35 and hub 18. A ring 44 having a plurality of spring tongues 46 floats within the cavity 42. The depending hook 40 contacts one of the spring tongues 46 on its inner surface and is biased radially inwardly thereby. The inner shroud ring half '35 has a number of lower lugs 43 which contact the ring half 34.

The outer end of the guide vane 24 has a disc 45 likewise journaled in aperture 4S in an outer shroud ring 50. An annular Teilon bushing 51 is also provided between the disc 45 and the outer shroud ring 50. The guide vane thus journaled in the inner shroud ring 34 and the outer shroud ring is mounted for rotation about the -axis which intersects the center of the apertures 36 and 48 and lies in plane A A containing the axes of rotation of all of blades 24. Pins 52 and v53 extend yfrom the upper surface of the disc 45 into an annular cavity 54 delined by the housing 16 and the outer shroud ring 50. Also disposed within the annular chamber 54 are a pair of control rings S6 and 5S. The rst control ring 56 has a plurality of arcuate slots 60 as can best be seen in FIGURE 7. The pins 52 are disposed in the slots 60. The control ring 58 likewise has a plurality of arcuate slots 62 which receive the pins 53. The curvature of slots 62 is opposite to the curvature of slots 60 and each of the slots 60 and 62 are slightly dished and the pins have lower partispherical surfaces on their heads so that the pins are received in the slots with a snap t. As can be seen in FIGURE 7, the control ring 56 and pins 52 are on one side of the plane A A While the control ring 58 and pins 53 are on the opposide side. Each control ring has a plurality of particircular indentations 61 which have a function to be described later.

An actuator indicated generally at 64 is shown in FIGURE 8. The actuator 64 comprises a stem 65 journaled in the housing 16 which terminates in a flanged portion 66. The flanged portion 66 is disposed in the annular chamber 54. A washer 67 having an aperture with a truncated conical surface is disposed about the stern on the youtside of housing 16. A sleeve 69 with a control arm 71 welded thereto has its edge terminating in a truncated conical surface. The ybore 59 of the sleeve 69 has a llat surface which mates with a flat (not shown) on portion 57 of stem 65 to prevent relative rotation between the parts. The inner end of the sleeve 69 has an axially extending split 72 so that as bolt 73 is tightened the end of sleeve 69 is wedged within the aperture of washer 67. Stem 65 is thus mounted in housing 16 for rotation about an axis 63 in plane A A and secured against axial movement. On the flanged portion 66 of the .I Y. Y Thus :it can .finlet guide arrangement which is rugged, light and cornactuator 64 are shown pins 68 and 7 0 which are journaled to control rings 56 and 58 respectively. In the preferred embodiment of the invention, two actuators spaced 180 apart are utilized while it is conceivable that also one or three or more could be used.

Operation A description of the operation of the device will now be given. As the control arm 71 on the actuator 64 is moved, stem 65 is rotated about axis 63. Assuming stem 65 is rotated clockwise in FIGURE 7control ring 56 will move upwardly and toward plane A-A simultaneously with control ring V53 being moved downwardly Y and toward the plane A-A. In three dimension, rings 56 and 58 are actually rotating in opposite directions about Vthe longitudinal axis of housing 16 while simultaneously moving axially toward plane A-'A. The movement of the control rings 56 and 58 will cause a clockwise rotation of each vane 24 about its axis 55 due to the presence of 'pins 52 and 53 Within slots 60 and 62 respectively. Thus, it can be seen that rotation of actuator'64 in either direction will impart a corresponding rotation to each of the guide vanes so that their exit angle can be changed to any desired setting.

Assembly i In assembling the vanes 24 to the control rings 56 and 58,the contro-l rings are brought together abutting atj the plane A--A as shown in FlGURE 9. In this position,

56 and 58 are then separated rotating the blades 24 to an Y operative position. The rings never abut except in the assembly operation and the curvatureot the slots is such that in any operative position the blades cannot rotate out ofthe slots and become disconnected from the control rings. Y This assembly thus eliminates the need Vfor providing means to lock the blades 24 to the control Yrings 56 and 58.

be seen that an improved variable pitch pact and can easily beV assembled into an existing com pressor design has been invented. I l

It should Ybe understood, of course, that the foregoing relaties to only a preferred Vembodiment of the invention Y y'used in connection with a compressor and that the inven- V tion is susceptible to numerous changes` and modifications and may be used as a variable vane stator stage in a turbine or in any iiuid'dynamic machinery where it is de-V .sirous to include a variable vane stage-whichY do not con- A `stitute departures froml the spirit and scope of the'invention. Y'

Iclaim: t 1. An inlet for a compressor, comprising a housing having an annular passage therethrough, a plurality of f guide vanes rotatably mounted in said annular passage, a first control ring connected to each guide vane and rotatable about the axis of said housing, a second control ring spaced from said iirst control ring, said second control ring connected t each guide vane and rotatable about said axis, actuating means to rotate said first and second control membersV simultaneously in opposite directions whereby said guide vanes are caused to rotate to change their exit angle, a hook extending axially from each of said guide vanes beyond said annular passage, and spring means beyond said annular passage operatively connected to said hooks whereby said guide vanes are biased axially as they are rotated,

2. An inlet for a compressor comprising a housing having inner and outer circular wa'lls defining an annular passage therebetween, a plurality of guide vanes journaled at opposite ends in said inner and outer circular walls for rotation about substantially radial axes of said housing, a first pin on each guide vane on one side otra plane containing said radial axes, a iirst control ring having a plurality of slots opening toward said plane, said slots journaling and retaining said first pins, a second pin on each guide vane on the opposite side of said plane, a second control ring having a plurality of slots openingV toward said plane, said slots journaling and retaining said 4. An inlet forY a compressor Vcomprising a housing, Y Y having inner and outer circular walls defining an annular passage therebetween, a plurality of guide vanes journaled at opposite ends in said inner and outer circular walls for rotation about substantially radial axes ofrrsaid housing, a first annular chamber in said housing spaced radially inwardly from said inner circular Wall andsubstan- Y tially coextensive with said guide vanes, a hook depending from each of said guide vanes and extending intoV said rst annular chamber, spring means in saidkfirst annular chamber operatively connected to said Yhook to s urge said guide vanes radiallyinwardly, a second Vannular chamber in said housing spaced radially outwardly from said outer circular wall and substantially coextensive with said guide vanes, a first pin on each guide vane on'one side of a plane containing said radial axes, said rst pins extendin-g into said second annular chamber, a iirst control ring disposed in saidjsecond chamber and journaled to said first pins, a second pin on each guide vane on theV Y opposite side of said plane, said second pins extending into said second chamber, a second control ring disposed in` said second chamber and journaled Vto said second pins, and actuating means to rotate said first and second Y control ringsV in opposite 'directions simultaneouslyv wherebysaid guide Vvanes are rotated about said radial axes.

-5. An inlertguideffor a compressor as described in claimy i 4 whereinsaid spring means comprises `a ring with 'aiV pluralityy of L-shaped spring blades, thesaxialy portionsV of said spring blades having their inner surfaces resiliently engaging said hooks.YV e 4 Y 6. An inlet guide for acornpressor comprising ahous-V Y Y ing having inner and outer circular walls defining'an au-Y nular passage ytherebetween, a plurality of guide vanes journaled at opposite ends in said inner and outer circular Walls for rotation about substantially radial axes of said housing, a iirst annular chamber in said housing spaced radially inwardly Vfrom said inner circular Vwall and sub-'f stantiallycoextensive Vwith said guide vanes, a hook de-V pending from each of said guide'vanes and extending into'r;V Y said iirst annular chamber, a ring having a plurality of,`

L-shaped spring :blades disposed withinsaid first annular chamber, the axial portionsY of said spring-blades having their inner surfaces in engagement with said depending hooks lto urge saidk guide vanes radially inwardly, a sec 5 Y ond annular chamber in saidhousing spaced radially outwardly xfromsaid outer circular wallY and substantially coextensive with said guide vanes, a first YpinV on eachV guide vane on one side of a'plane containing Said radial axes, said first pins extending into said second annular chamber, a first controlk ring disposed in Vsaid second chamber andV journaled to said first pins, asecond pinlA on each guide vane on the opposite side ofy said plane,4 said second pins extending into said second annular chaniber, a second control ring disposed in said second chamber and journaled to said second pins, an actuator journaled in said housing for rotation about a radial axis` in said plane, said actuator having a portion Vthereof extending into said second annular chamber and rotatably connected tov saidY first and second control rings whereby rotation of said actuator winds said control rings in opposite directions toward said plane to rotate said guide vanes about their radial aXes.

7. In an inlet for a compressor having a housing with inner and outer circular walls defining an annular passage there-between, and a plurality of guide vanes journaled at opposite ends in the inner and outer circular walls for rotation about substantially radial axes of said housing; an annular chamber in said housing spaced radially inwardly from said inner circular wall and substantially coextensive with said guide vanes, a hook depending from each of said guide vanes and extending into said annular cham'ber and spring means in said first annular chamber operatively connected to said hooks whereby said guide vanes are always resiliently urged radially inwardly as said guide vanes are rotated to change their angle of attack.

8. In an inlet -for a compressor having a housing with inner and outer circular walls dening an annular passage therebetween and a plurality of guide vanes journaled at opposite ends in said inner and outer circular walls for rotation about substantially radial axes of the housing;

an annular chamber in said housing spaced radially inwardly from said inner circular wall and substantially coextensive with said guide vanes, a hook depending from each of said guide vanes and extending into an annular chamber and a ring having a plurality of L-shaped spring blades disposed within said annular chamber, the axial portions of said spring blades having their inner surfaces in engagement with said depending hooks whereby said guide vanes are resiliently urged radially inwardly.

References Cited bythe Examiner UNITED STATES PATENTS 1,544,288 6/1925 Ormer 253--78 X 2,337,861 12/1943 Adamtchik 230-114 2,923,459 2/1960 Taylor 230-114 FOREIGN PATENTS 1,136,350 9/1962 Germany.

DONLEY I. STOCKING, Primary Examiner. HENRY F. RADUAZO', Examiner. 

1. AN INLET FOR A COMPRESSOR, COMPRISING A HOUSING HAVING AN ANNULAR PASSAGE THERETHROUGH, A PLURALITY OF GUIDE VANES ROTATABLY MOUNTED IN SAID ANNULAR PASSAGE, A FIRST CONTROL RING CONNECTED TO EACH GUIDE VANE AND ROTATABLE ABOUT THE AXIS OF SAID HOUSING, A SECOND CONTROL RING SPACED FROM SAID FIRST CONTROL RING, SAID SECOND CONTROL RING CONNECTED TO EACH GUIDE VANE AND ROTATABLE ABOUT SAID AXIS, ACTUATING MEANS TO ROTATE SAID FIRST AND SECOND CONTROL MEMBERS SIMULTANEOUSLY IN OPPOSITE DIRECTIONS WHEREBY SAID GUIDE VANES ARE CAUSED TO ROTATE TO CHANGE THEIR EXIT ANGLE, A HOOK EXTENDING AXIALLY FROM EACH OF SAID GUIDE VANES BEYOND SAID ANNULAR PASSAGE, AND SPRING MEANS BEYOND SAID ANNULAR PASSAGE OPERATIVELY CONNECTED TO SAID HOOKS WHEREBY SAID GUIDE VANES ARE BIASED AXIALLY AS THEY ARE ROTATED. 